As I said in the OP, the Eberron setting provided a massive amount of support for Dragonmarks. Amongst this support is prestige classes that focus on improving your Dragonmarks or providing abilities that use your Dragonmarks and their SLAs.
The following sources have prestige classes that either require a Dragonmark or improve upon their abilities.
- Eberron Campaign Setting
- Sharn, City of Towers
- Magic of Eberron
- Explorer's Handbook
Entry Requirements: Must be a Dragonmarked race, have 7 ranks in two skills (meaning 4th level at minimum), Favored In House and Least Dragonmark (any).
Progression: d8 HD, 4+Int Skills, great saves, Medium BAB, and a shitty skill list. Taking levels in this class means you are dedicated to advancing your Dragonmark, not for the awesome stat progression.
Abilities Overview: For starters, you get Lesser Dragonmark as soon as you take the 1st level in this class, and Greater Dragonmark at 4th level (so there's a nice benefit). Saving feats is important for any build, especially when your entire concept is designed around using feats. You also get a minor diplomacy bonus, but that isn't as important for this concept. Extra action points are always welcome when they are in use (there's also some RAW trickery which gives you 8 additional action points instead of the intended 2).
Perhaps the most important ability provided by this PrC is the improved CL and extra daily uses of the SLAs. The CL increase for the Least Dragonmarks is minimal (ups them from CL 1 to CL 6, so they don't suck entirely if they are CL reliant). Overall, this is an excellent PrC for characters using the Healing, Hospitality, Passage, Sentinel, Shadow, Storm, and Warding marks. Consider the full 5 levels of this PrC if it won't cut into your other class features.
A quick note; there is an alternate PrC called Child of Khyber, which is almost identical to this PrC except it provides bonuses to Aberrant Dragonmarks. It was printed in an online article, so a quick Google will pull it up.
Heir of Siberys
Entry Requirements: Must be a Dragonmarked race, 15 ranks in two skills (meaning 12th level minimum), Heroic Spirit, and cannot have an existing Dragonmark at all.
Progression: d6 HD, medium BAB, great saves, 2+Int skill points. All of your existing class skills make up the skill list for this PrC. So, in a way, this PrC is weaker than Dragonmarked Heir.
Ability Overview: Let me make one thing perfectly clear: If you are gunning for this PrC, it means you are forgoing every other Dragonmark grade and want the most powerful SLA you can get, specifically so you can abuse it. The spellcasting progression may or may not matter to you; what you care most about is the SLA.
And wow, some of those SLAs are really good. True Creation, despite the errata, can save lives. As can Mass Heal, Moment of Prescience, and Prismatic Wall. The Mark of Finding, Shadow, and Scribing aren't particularly powerful though, so it's best to look into other options first.
Entry Requirements: Hide 4 ranks, Sleight of Hand 4 ranks, Bluff 8 ranks, Least Dragonmark (Hospitality), and must receive special training.
Progression: d6 HD, medium BAB, two good saves, 6+Int skills. The skill list is good for sneaking around, but it lacks Disable Device. Not exactly a good follow up for a trapfinder character.
Ability Overview: Ok, this PrC makes no sense to me and is overall weak. It bills itself towards espionage, so I'm not going to suggest levels in this if your DM is combat-focused, but even for it's intended purpose the class rather sucks. It focuses on the two SLAs the Least Dragonmark provides, but the improvements made to those abilities do not help a PC nearly as much as it should. Overall, I'd call this a DM-focused PrC because of how bad the abilities are. The 3rd level ability lets you create poisons, but none of them have a decent save DC. Even at the lower levels this ability is terrible for an NPC because the NPC can simply buy an actually potent poison that could do some real damage. The capstone ability is decent, but not worth 5 levels at all. Ultimately, I recommend avoiding this PrC entirely, even if you are going for the Mark of Hospitality's Greater mark.
Blade of Orien
Entry Requirements: BAB +3, Spot 3 ranks, Least and Lesser Mark of Passage (for Dimension Leap and Dimension Door, respectively).
Progression: d8 HD, full BAB, good Ref saves, 4+Int skills and a solid skill list for a melee class. All around easy requirements mixed with a solid base. You can get these requirements by taking Dragonmark Hier levels, which will be a good idea for this PrC as the extra daily uses of the Least and Lesser mark will be valuable.
Ability Overview: First and foremost, it progresses your Dragonmark's CL as though it were levels in Dragonmarked Hier, but only up to 5 levels (ask your DM to house rule this to the full 10 levels, as it really won't break anything). It then allows you to get additional uses of Dimension Leap and allows you to move in 5ft increments instead of 10ft increments, and allows you to use the Dimension Leap ability as a Move action, making the mark's effect more tactical. At 2nd level, you can bring multiple creatures with you when you use the Dimension Leap ability, allowing you to set up ambushes or bypass mooks with ease. At 3rd level, you can steal things or toss them to others using your Dimension Leap, meaning you can really screw with people or provide equipment support by being a walking Haversack. You can also use it to switch places with an ally, or to send your ally halfway across a battlefield, or start teleporting enemies, or invoke the Blink spell on yourself. Finally, at 10th level, you can use the Swift Leap class feature to take Full Attacks as a Move action!
To say this PrC is worth every level would be an understatement. The Blade or Orien is very practical, tactical, and otherwise useful for a Dragonmark-focused character. BTW, the Capstone? It lets you take a Full Attack as a Move action. Dimension Leap lacks the "Can't take any other action" clause that Dimension Door has. Hats off to you WotC, you made a flavorful and efficient PrC that I really like!
Entry Requirements: Knowledge (Arcana) 4 ranks, Survival 6 ranks, must be a member of House Cannith and in good standing, must have either Least or Siberys Mark of Making.
Progression: d8 HD, medium BAB, two good saves, 2+Int skills with UMD amongst the list, and it provides Infusions (although it doesn't progress existing ones).
Ability Overview: The Dragonmark Conduit ability isn't all that impressive, especially compared to the fact that this PrC improves your Dragonmark's CL (which is important for Minor/Major Creation). The real jewels here are the Infusions (which have a CL penalty, but very few Infusions allow SR anyway), the Blindsense ability, and UMD as a class skill. If you were going for Dragonmark Heir with the Mark of Making, this isn't a bad follow up to it. If the campaign will be taking place in the Mournlands, levels in this PrC will help a little. Otherwise you can skip out on this.
Entry Requirements: Any Lawful, Gather Information 4 ranks, Least Dragonmark (Sentinel), and must be in good standings or get permission to join the Wardens from the house.
Progression: d10 HD, full BAB, good Fort save, 4+Int skills with a skill list similar to Blade of Orien. All around, not bad.
Ability Overview: I'm being a bit harsh on this PrC, but the truth is the class features work on Evil Outsiders almost by default. Hell, the capstone's +6 to Will saves works if one of your party members has broken a law within the past few months (and knowing PCs, they likely have). So this PrC is nothing but benefits, if minor ones.
The real gems of this PrC are the benefits you get when dealing nonlethal damage. If you ever do 15 or more points of damage, they have to save or be Shaken for 1 round, and later one they have to save or be Stunned for 1 round (then Shaken for 1d4 rounds afterwards). So if you can make 4 attacks/round, you can potentially reduce an enemy to a sobbing wreck just by hitting them! Also, Mettle and Improved Uncanny Dodge for free.
So yeah, this PrC is similar to those builds that focus on Intimidate, but without needing skill points to use it (seeing as it triggers off of your damage automatically). Given the save DC for the Shaken effect is 5+Damage (later 10+Damage), it should be really easy to scare your enemies shitless for a round. This is great for battlefield control, as it forces enemies that aren't immune to fear to waste actions fleeing as fast as they can!
Otherwise this PrC provides minor bonuses and boosts your Dragonmarks. This is a perfect finisher for a melee build, and the Mark of Sentinel isn't too shabby otherwise.
Entry Requirements: BAB +4, Least and Lesser Dragonmark (Finding), and either Tracking or Urban Tracking.
Progression: Identical to the Ranger, minus spellcasting. Seriously, it's carbon-copy.
Ability Overview: As one could expect for the Mark of Finding, this PrC is all about finding people. Really, the only things this PrC offers are additional uses of your Dragonmark abilities and Hunter's Insight. You'd be better off with actual Ranger levels than wasting levels in this PrC.
Entry Requirements: Knowledge (Arcana) and Sense Motive 4 ranks, Least and Lesser Dragonmarks (Detection), Able to cast 2nd level spells, must be a worshiper of Aureon, and must have received training from the Voice of Aureon.
Progression: d6 HD, medium BAB, good Will, 4+Int skills, a meh skill list, and 5/5 spellcasting advancement.
Ability Overview: As if Divinations couldn't break the game all ready, you now have a class feature that acts as a free Divination spell and a perfect excuse for the DM to railroad the party. So that's a mixed message right off the bat. This PrC is a bunch of SLAs, but the capstone ability removes all traces of detective elements from the Eberron setting itself. The DM has to be prepared for this if you plan on taking levels in the class, or else things get complicated.
For that reason alone I ask you to avoid this class, or at least it's capstone, unless your DM has handled these kinds of abilities with a reasonable and rational hand in the past. This is a prime example of abilities that can end a campaign before it starts, so inform the DM prior to both the campaign beginning and to taking levels in this PrC.
Entry Requirements: Base Fort Save +3, Heal 8 ranks and Knowledge (Nature) 4 ranks, and Least/Siberys Dragonmark (Healing).
Progression: d8 HD, medium BAB, two good saves, 2+Int skill points and a meh skill list. Notably this is not only a 4/5 casting class, it provides you Adept spellcasting if you did not all ready have spellcasting abilities yourself.
Ability Overview: First and foremost, this PrC is based around disease. As any D&D gamer will tell you, that means this class is irrelevant past 6th level at the latest. The only reason to take levels in this class is if the DM has modified the disease rules such that they are an actual threat and if you all ready had the prerequisites.
Entry Requirements: BAB +4, Hide and Move Silently 4 ranks, Least Dragonmark (Shadow, must have the Darkness ability), must be proficient with Martial weapons.
Progression: d8 HD, full BAB, two good saves, 6+Int skills and an all-around useful skill list (for as long as skills remain useful anyway).
Ability Overview: This PrC is basically the Dragonmarked version of the Shadowdancer, only not so fail-tacular. It gives you the ability to use Deeper Darkness, to ignore Darkness and Deeper Darkness automatically while using that ability, to blind enemies completely for a decent duration, and to invoke concealment as a Swift action. If you were going for Dragonmarked Heir (Shadows), and wanted to be a melee character, this PrC is actually pretty good for the concept (except for that whole Elf problem). The capstone is useful no matter what, but the rest of the abilities are useful too. Not nearly as good as Blade of Orien, but still pretty good.
Entry Requirements: 4 ranks in Disable Device, Hide, Knowledge (Architecture and Engineering), and Open Lock, Dodge, Trap Sense +1, and must be a member of House Kundarak.
Progression: d6 HD, medium BAB, two good saves, 6+Int modifier skill points and a great skill list.
Ability Overview: Oddly, this is the only Dragonmarked PrC that doesn't actually require the mark (as you can join House Kudarak without having one). It still uses Dragonmarks for its class features, but it doesn't actually require you to have one. Still, the Mark of Warding is one of the best there is, so no harm in taking it. Even stranger is that the first level ability is for spellcasters, but the class does not progress spellcasting.
Really, there isn't anything interesting in this PrC other than a minor ability at 6th level. The class isn't nearly as good as the Dragonmark itself.
Entry Requirements: BAB +4, 4 ranks in Balance and Tumble, Least Dragonmark (Storm, Gust of Wind).
Progression: d10 HD, Full BAB, two good saves, 4+Int skills with a decent skill list.
Ability Overview: This PrC provides a couple of SLAs that go well with your Dragonmark, but the most important thing is that it improves your Gust of Wind ability. Given that Gust of Wind offers SR, this isn't that powerful, but the ability can come into play quite often against humanoid opponents. Gust of Wind can end encounters in certain terrain conditions, so it isn't exactly a bad choice of PrC for this purpose. Just don't expect the class features to be useful against anything with SR or that's Huge+ (although that's always been a weakspot for melee characters).
Entry Requirements: Profession (Scribe) 4 ranks, Least Dragonmark (Scribing, Arcane Mark), able to prepare 3rd level spells or able to imbue 3rd level Infusions, and must complete a special task assigned by the Viceroy of the Ninth College.
Progression: d4 HD, half BAB, good Will saves, 2+Int skill points with a good skill list, 4/5s casting advancement.
Ability Overview: While it progresses Artificer Infusions, the progression decrease and loss of craft pool is not worth levels. And given that it is focused on Scrolls (AKA the second-most annoying consumable out there), I'd say this almost isn't worth levels. However, the Metamagic Scroll and the save DC boost is actually somewhat useful. Still, it's a PrC based around scrolls and it costs you a CL. I wouldn't take levels in it myself.
Entry Requirements: BAB +4, 3 ranks in Handle Animal, Knowledge (Arcana), and Knowledge (Nature), 4 ranks in Ride, Mounted Combat, must be a member of House Vadalis, and must have an Animal Companion or Special Mount.
Progression: Identical to the Ranger, except the spellcasting (that got condensed into 10 levels). Prestige Ranger is awfully good for a follow-up.
Ability Overview: Really, the only draw for this class is that both you and your companion/mount gain the Magebred template, and that you get Ranger spellcasting for free. Wild Cohort is the easiest way to enter the PrC, and it progresses your Dragonmark as usual. If you want, you can do a psuedo-Super Mount with this class, but it isn't exactly the best class for the job.
Cannith Wand Adept
Entry Requirements: Spellcraft 6 ranks, Use Magic Device 8 ranks, Craft Wand, Wand Mastery, and either Favored in House (Cannith) or Least Dragonmark (Making).
Progression: d8 HD, medium BAB, good Will saves, 2+Int skill points with a good skill list.
Ability Overview: Let me make one thing perfectly clear: Entering this PrC will cost you caster levels no matter what. You need to be eligible for Craft Wand, which requires a CL. This class does not advance any form of spellcasting.
With that out of the way, here's the notable abilities: Add your class level to the save DC of a wand, use two wands at the same time, mimic using an action point (except you can roll up to 4d6 at a time), and get a beter Dragonmark. This class largely sucks seeing as the Dual Wand Wielder feat exists in CArc. Really, the best ability is the improved save DC. A level-dip at most is all I could ever recommend.
Entry Requirements: Craft (Alchemy) 8 ranks, Brew Potion, and either Favored in House (Cannith) or Least Dragonmark (Making).
Progression: d4 HD, half BAB, good Fort save, 2+Int skill points with a poor list, 5/5 casting progression.
Ability Overview: Remember what I said about Unbound Scroll? How it uses the second-worst consumable item in the game? This PrC focuses on the worst there is: Potions. As such, I hate the PrC with a passion that is only rivaled by my hatred of elves. Seriously, this PrC is not worth it. Potions are overpriced, underpowered, and impractical.
The only redeeming quality is the capstone, which lets you cheat the spells/day restriction for up to 3rd level spells. Said cheating can be replicated much easier by crafting wands, and you meet the requirements for the feat two levels into this PrC.
Entry Requirements: 8 ranks in Knowledge (History) and Knowledge (The Planes), able to cast 3rd level spells, must of had a vision.
Progression: d4 HD, half BAB, good Will saves, 2+Int skill points with a meh skill list, 9/10s casting advancement.
Ability Overview: Ok, the only reason this class is getting mentioned is because the capstone grants you a Dragonmark. Said Dragonmark can be changed each day, and you can get a Greater mark without needing a Least or Lesser. You don't need to be a member of the appropriate race.
The problem is twofold: Getting there and using that mark. You see, you have a 1/4 chance of dying just from taking the first level in this PrC. Said death, if it happens at the right level, will render your progression in this class impossible. And, at the DM's option, these are mandatory for you to progress to 10th level. If you get Swallowed Whole at 1st level, you have to let it happen (which can kill you). If you get Die, you have to die and get a True Rez or Revivify in order to progress. Even worse, getting to leve 10 means every dragon studying the Dragonic Prophecy now wants you deader than dead. The class feature states that they will stop at nothing to get you killed in such a way that you cannot be resurrected.
And as for using the mark: You can't qualify for Dragonmark PrCs without spending the feat anyway. So the CL you get with that Dragonmark the capstone provides is ultimately locked in stone. And if you do spend the feat, you get to debate with your DM what the hell the ability means when it says "you can change your Dragonmark each day", as the ability isn't completely explained in a way that is coherent. Finally, it makes no mention of meeting the racial requirements for the Dragonmarks you gain.
So you have to deal with all kinds of hell to get there. While the ability is nice, you're a spellcaster. You have better options than this. Much better ones. I do not recommend this class for that reason.
Child of Khyber
Entry Requirements: Any nongood, 7 ranks in two different skills, Abberant Dragonmark.
Progression: d8 HD, medium BAB, three good saves, 4+Int skill points with a decent skill list.
Ability Overview: This is basically the counterpart to Dragonmarked Heir, with one major exception: Aberrant Burst. The ability is decent for anyone using Aberrant marks, as it raises the CL and DC by 3 each.
The only problem is that the PrC doesn't mention any other CL increases for your Aberrant marks, meaning you have to get the DM to extrapolate from the feats themselves. That said, several Aberrant Dragonmark SLAs are very powerful and, more importantly, useful. Consider this if you are using one.